Poincaré-Chetaev变量下广义Routh方程的对称性与守恒量

根据Rumyantsev提出的Poincaré-Chetaev变量下的广义Routh方程,用无限小变换的方法研究它的对称性与守恒量.得到守恒量存在的条件和形式.该结果比以往的Poincaré-Chetaev方程的相关结论更一般.最后,举例说明结果的应用.     

广义Birkhoff系统的梯度表示

研究广义 Birkhoff 系统的梯度表示. 给出广义 Birkhoff 系统可成为梯度系统的条件. 利用梯度系统的性质来研究广义 Birkhoff 系统的稳定性. 举例说明结果的应用.     

Structure-preserving algorithms for autonomous Birkhoffian systems

The Pfaff-Birkhoff variational principle is discretized,and based on the discrete variational principle the discrete Birkhoffian equations are obtained.Taking the discrete equations as an algorithm,the corresponding discrete flow is proved to be symplectic.That means the algorithm preserves the symplectic structure of Birkhoffian systems.Finally,simulation results of the given example indicate that structure-preserving algorithms have great advantage in stability and energy conserving.     

关于非完整系统的Ценов方程和Mac Millan方程

Ценов方程和Mac Millan方程是非完整力学史上较晚出现的运动方程.这些方程的建立不仅有历史意义,而且有理论和应用的优势.本文对Ценов方程和Mac Millan方程的形成提供一些史料,并提出一些看法.     

Lie Symmetry and Non-Noether Conserved Quantity for Hamiltonian Systems

A non-Noether conserved quantity for the Hamiltonian system is studied. A particular infinitesimal transformation is given and the determining equations of Lie symmetry are established. An existence theorem of the non-Noether conserved quantity is obtained. An example is given to illustrate the application of the result.     

约束系统动力学的研究进展

综述约束系统动力学的研究进展,包括经典分析力学的理论与应用,近代分析力学的发展,以及Birkhoff系统动力学的出现,并提出未来发展方向的建议.     

Poinearé-Chetaev变量下广义Routh方程的对称性与守恒量

根据Rumyantsev提出的Poincare-Chetaev变量下的广义Routh方程,用无限小变换的方法研究它的对称性与守恒量.得到守恒量存在的条件和形式.该结果比以往的Poincare-Chetaev方程的相关结论更一般. 最后,举例说明结果的应用.     

具有完整约束的变质量系统的机械能守恒律

研究具有双面理想完整约束的变质量力学系统的机械能守恒律.首先,利用系统的运动微分方程,获得能量变化方程,并给出机械能守恒律存在的充分必要条件.然后,提出具有守恒律的27种情形.最后,举例说明.     

Birkhoff系统的广义斜梯度表示

提出广义斜梯度系统并研究Birkhoff系统的广义斜梯度表示.给出系统成为广义斜梯度系统的条件.利用广义斜梯度系统的性质来研究系统解的稳定性.举例说明结果的应用.     

Birkhoff symmetry and Lagrange symmetry

The purpose of this paper is to study the symmetry of first order Lagrangians and the corresponding conserved quantity. The relation between the Lagrangians and the Birkhoff’s functions and the Birkhoff symmetry of Birkhoffian systems are used to obtain the symmetry of first order Lagrangians and the corresponding conserved quantity. Two examples are given to illustrate the application of the result.